An Egyptian woman kisses a poster of General Abdel Fattah al-Sissi in Cairo. (KHALED DESOUKI/AFP/Getty Images)

Three years and two days after the start of the Egyptian revolution, Defense Minister Abdel Fatah al-Sissi had two major breaks in his burgeoning career as Egypt's de facto military ruler. The Supreme Council of the Armed Forces, which runs the military, voted unanimously to endorse Sissi for the presidency. And interim President Adly Mansour promoted Sissi, until now a general, to the rank of field marshal.

The subtext of both moves is not difficult to deduce: Sissi appears to be edging toward the presidency, which was already the case before today's announcements.

Still, there's an interesting and revealing history to the "field marshal" title, one that transcends just Egypt. Although it's supposedly just a very high military rank, in practice it and similar variations are often used to confer political authority on a military official.

Probably the starkest example is North Korea. First national leader Kim Il Sung, as part of his consolidation of power, had himself appointed as Wonsu, which means Marshal and was then the country's highest military rank. In 1992, as the Soviet Union's collapse shook North Korea, Kim promoted himself to Dae Wonsu, or Grand Marshal. His son, Kim Jong Il, became Marshal as he was eased into power himself, but wasn't promoted to Grand Marshal until after his death. The third generation of leaders, Kim Jong Un, likewise became Marshal during his transition to power but is not yet a Grand Marshal.

Pakistani military leader Muhammad Ayub Khan, who seized power in a coup in 1958, promoted himself to grand marshal while in office. So did Ugandan dictator Idi Amin, who like Khan cultivated an image of beloved national hero. In 1921, a time of political chaos in China, nationalist leader Sun Yat-sen set up a military government in the southern province of Guangzhou and made himself grand marshal. And so on.

The fused military-political role of the field marshall is actually inherent in the title itself. It was first used in Medieval Europe to mean the keeper of the king's horses; marshall literally translates, in several Western European languages, to "horse keeper" or "horse servant." The proximity to the king and his supposed divinity, as well as the fact that monarchs were often bad generals, gave this right-hand military man a degree of political legitimacy as well as independent authority.

Even the United States hasn't been able to resist the title. In 1936, during the Philippines' slow transition from American possession to independence, the famously imperious Gen. Douglas MacArthur became "field marshal of the Philippine Army." The imperial-sounding title signified his authority in the country, which was political as well as military.

At other times, the title has been used to mollify or buy off military leaders. Afghan President Hamid Karzai promoted Defense Minister Mohammad Fahim to field marshal in 2004, after Fahim had backed Karzai's presidential election opponent, in apparent retaliation for Karzai passing over Fahim for the vice presidency. In 1945, British Gen. Bernard Montgomery objected to having his command of the allied forces handed over to U.S. Gen. Dwight Eisenhower. So Winston Churchill promoted Montgomery to field marshal as a sort of consolation prize, even though he had actually lost authority rather than gained it.

Of course, there are times when it's been a straight promotion for military service, although typically in countries where military prestige and political authority are already blurred. Egypt, for its part, has had four other field marshals in its history. Gen. Mohamed Hussein Tantawi, for example, became field marshal in 1991. But it's up for debate whether this promotion was for successfully leading an Egyptian military unit in that year's U.S.-led Gulf War or was part of his ascension to defense minister, also in 1991.

As for Sissi, the default assumption seems to be that this is meant to bolster his political legitimacy before sending him up for the presidency. A small subset of observers, though, have wondered whether maybe this is a Montgomery-style consolation prize meant to gently ease him away from the presidency. Whatever message is being sent with this promotion, it certainly seems to about politics and not military matters. And, in using an ostensible military title for political purposes, Sissi joins a long line of field marshals from around the world.